| // rsbegin.o and rsend.o are the so called "compiler runtime startup objects". |
| // They contain code needed to correctly initialize the compiler runtime. |
| // |
| // When an executable or dylib image is linked, all user code and libraries are |
| // "sandwiched" between these two object files, so code or data from rsbegin.o |
| // become first in the respective sections of the image, whereas code and data |
| // from rsend.o become the last ones. This effect can be used to place symbols |
| // at the beginning or at the end of a section, as well as to insert any required |
| // headers or footers. |
| // |
| // Note that the actual module entry point is located in the C runtime startup |
| // object (usually called `crtX.o), which then invokes initialization callbacks |
| // of other runtime components (registered via yet another special image section). |
| |
| #![feature(no_core, lang_items, optin_builtin_traits)] |
| #![crate_type = "rlib"] |
| #![no_core] |
| #![allow(non_camel_case_types)] |
| |
| #[lang = "sized"] |
| trait Sized {} |
| #[lang = "sync"] |
| auto trait Sync {} |
| #[lang = "copy"] |
| trait Copy {} |
| #[lang = "freeze"] |
| auto trait Freeze {} |
| |
| #[lang = "drop_in_place"] |
| #[inline] |
| #[allow(unconditional_recursion)] |
| pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) { |
| drop_in_place(to_drop); |
| } |
| |
| #[cfg(all(target_os = "windows", target_arch = "x86", target_env = "gnu"))] |
| pub mod eh_frames { |
| #[no_mangle] |
| #[link_section = ".eh_frame"] |
| // Marks beginning of the stack frame unwind info section |
| pub static __EH_FRAME_BEGIN__: [u8; 0] = []; |
| |
| // Scratch space for unwinder's internal book-keeping. |
| // This is defined as `struct object` in $GCC/libgcc/unwind-dw2-fde.h. |
| static mut OBJ: [isize; 6] = [0; 6]; |
| |
| macro_rules! impl_copy { |
| ($($t:ty)*) => { |
| $( |
| impl ::Copy for $t {} |
| )* |
| } |
| } |
| |
| impl_copy! { |
| usize u8 u16 u32 u64 u128 |
| isize i8 i16 i32 i64 i128 |
| f32 f64 |
| bool char |
| } |
| |
| // Unwind info registration/deregistration routines. |
| // See the docs of `unwind` module in libstd. |
| extern "C" { |
| fn rust_eh_register_frames(eh_frame_begin: *const u8, object: *mut u8); |
| fn rust_eh_unregister_frames(eh_frame_begin: *const u8, object: *mut u8); |
| } |
| |
| unsafe fn init() { |
| // register unwind info on module startup |
| rust_eh_register_frames( |
| &__EH_FRAME_BEGIN__ as *const u8, |
| &mut OBJ as *mut _ as *mut u8, |
| ); |
| } |
| |
| unsafe fn uninit() { |
| // unregister on shutdown |
| rust_eh_unregister_frames( |
| &__EH_FRAME_BEGIN__ as *const u8, |
| &mut OBJ as *mut _ as *mut u8, |
| ); |
| } |
| |
| // MSVC-specific init/uninit routine registration |
| pub mod ms_init { |
| // .CRT$X?? sections are roughly analogous to ELF's .init_array and .fini_array, |
| // except that they exploit the fact that linker will sort them alphabitically, |
| // so e.g., sections with names between .CRT$XIA and .CRT$XIZ are guaranteed to be |
| // placed between those two, without requiring any ordering of objects on the linker |
| // command line. |
| // Note that ordering of same-named sections from different objects is not guaranteed. |
| // Since .CRT$XIA contains init array's header symbol, which must always come first, |
| // we place our initialization callback into .CRT$XIB. |
| |
| #[link_section = ".CRT$XIB"] // .CRT$XI? : C initialization callbacks |
| pub static P_INIT: unsafe fn() = super::init; |
| |
| #[link_section = ".CRT$XTY"] // .CRT$XT? : C termination callbacks |
| pub static P_UNINIT: unsafe fn() = super::uninit; |
| } |
| } |